SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecc4ecc0362e3d819fa831ce73066082e170366af9d149ffc167c039dd2a1db6' 
  AND token = 'csAGfmRnwowF3P9164ANm/rvShRbvWDCiA+LSxcdlU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}