SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32b31f2c63a607d7119611794a22199168a99d299ef4248667b00ed9e0bbb437' 
  AND token = '7DfOh6/2dsKDm7tHozZIvIRlO4kPcdSamJRpSVae90I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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