SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11526b47358d854c2b61db8a8cc6c95a3acc8b0b800daf40101c37f0d2a88a11' 
  AND token = 'lZCVoIGRL+mWw+OAi1XSrYBfEFM8BrqgKPXluMEVI9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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