SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b4b304798e39a06e0fd3e1b0bece6dadc3a515986d51f4270023ca934394b90' 
  AND token = 'owlaMv3rKBoK3W2xpUMrsuNDh8MnwZztK4UtEf3tULU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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