SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca48309365bb8251f508dc62b4084285e047ce0d0c24419c828cc8374fd7101' 
  AND token = 'ljZ8Bj1kkmv4VWjwXGV+fihTvBxv3MD+X7C+xARjrdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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