SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c46652c7650d96ad04a61469dc1fdcb300958979c605a650ca2cbc4e99ad5a4c' 
  AND token = 'dlacO+Vg/HCWpMD2yjGA03hnkUhoiiX13djv/g6VfHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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