SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e03fd8045eea7d0736271b3998cd3bc5379176a3da84315bbac84a137b9e125' 
  AND token = 'p/BvLaI64Yws0tojphcMFIgx0+B/MwkAGjvI9rR9vk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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