SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f1441991f756945d9da6f1960f6880a2c9702baabb86d51573cda240b3679a2' 
  AND token = 'y2UQ+wZQO712VXouquKu/UuJyDado3ypBsqhpXahGAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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