SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b92da28565324a80192159f2eb596b63e80ca430307eb80fc08c36fc1a72150f' 
  AND token = 'YStxkNXotVBcQx4uqkD+sKpI42J0TMtd0+SZxxb91Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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