SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab56589839dbcbb608b1027436188a3adff816c517476b4e6a6bf4b5f243e536' 
  AND token = 'WvGAH+hG6p+bGtRcsO552Y1Iil4gaVuJ56cpnFhdDTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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