SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde38067949781b47785797d8f3b6ba73abc83719787ca3aa84341987c5db150' 
  AND token = 'DhrGocWCZnCXiRfkg7YEdAx0myrpDZjpfp/CwOEuB8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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