SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4849269bdc157205f243e5fcfaa9c982fa11f9d3b709f1f358995cb857c02f0a' 
  AND token = '6oxpD8Nc7/FFEJw6Li71p+PWes91pZihQQ0KguOzGY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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