SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a139a82ef217cdc624d936d675d1fa1e08d73dc8d7b22125c7a035e77358c08' 
  AND token = '7QnWBknS/NU5NmHm4zsoOHVoB9XxQmPYVkkikySH06M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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