SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01c20278b2c293fd2e5986c7366e359756f280b119e11927e0385931028d17f1' 
  AND token = 'wZ5Kc550llvP6ancck5BhelUODwDUf9tLWlmj9NQ5Dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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