SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f2d7ec283fa1de822af67baed59a82d412d08b6a6c854d0de459ac09e1a8796' 
  AND token = 'cxKEYk1udtqmPBwudAATknC7FdqcpPxUW8/fCz8VXKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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