SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3216d602b4615387c3b1a143cc6db5ffdd8ed104a27cfaf9be24183fd75fe826' 
  AND token = '8y7BBzpiKw3tGpdPTr/1uOifM2ZAh+gs7Mfqk8XX5I4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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