SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6338836d0db66d10c1ff728bf02b8331d466f2160e483fc54c92ca54633d239' 
  AND token = 'pYqn5IlNaNOAkj9S1Ug8Qvhy9DPyyXTYMKGriNJj+AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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