SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53658560f5517a9657b460b49f3cf8ea8e5b6f2a49d73526488f71a514d6634a' 
  AND token = 'qv4ja0XLRdiiITBjrSUfRrYMSqKF+0aiRT71Et7BvDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}