SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8531d2d1d60fc860d53f5cca09e109264b15b3cad7438e5457cf995740d1f085' 
  AND token = 'Jn1roqOav4fZxY+BvILCO4EAPctZuUdnks4BlZVHq1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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