SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd4b8461f4d407cd2f56b092b115cc810d07ddffa3cddf7fe1b3def46c0b87fa' 
  AND token = 'YyaA2YiTIeGds1SfHNZIo5H1HqiaT3CSKeKbr8aQK5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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