SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36361264ff691bf307d743dbfe80793577e5832780e906c0632033a6981f794f' 
  AND token = 'SxOoXu/P9utQtwzCU4mzfqVF/wSUHcAWEmvXyYTFR6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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