SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9956875e58c52a88b734aff5195487266cbf6645a7c61917b864b5b38dba882' 
  AND token = '13AdDc5u3JYE8U4Y3OnMsyR0zriiPbu8yUHqrbuSVAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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