SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '565fb27118546d346be39f2abc454bf3d4a24065365edaf8f4011a5df60891d0' 
  AND token = 'oBClFwF4TkFsMWHSHi/jxlBfZnbsGEOgBFeKYJiy/iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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