SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6026697303b87725801dc2e083995678cd7d4b18cd14fc349c6fbe6535a7c6ba' 
  AND token = 'aBocBbByyEZ1m14JxY/NZ2I5/wOVOG2Ze4Dz0sMx5+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}