SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db9b47f8022ea66dacbdb2b24ac2f259a714e1681687982a17ab93e3678c5cbe' 
  AND token = 'I2jDfpfm5PBOAdPiKUImmxbfOIIw6dQAc9AGzzQi++M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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