SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdcadc5061de8af4bbe18572115ae17a0774bbce83f890da3ccb236163a3a785' 
  AND token = 'xeE3gy1teEaWPsduCDxmcPBE3yARU9PF9s2AIH0KYO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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