SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '049515e99140c97c33d2bd6d5a2a154b01640aede6bd017449fbb83590249333' 
  AND token = 'T8K0o3aqVXFvBkqyAu84XRkBMVCvS4jLmUEyvfYbl4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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