SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c4041b059d37960addfa3ebbe2b332f32b2562962c658f2ae090c30d3ff5129' 
  AND token = 'xWbAF7GsZf+4tggDr4TAWPRhdnEEdZ2QAMcvq8Blpsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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