SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d8779e5e269bbc8be248e771865e9b7ad7fcd7bbb783739f713940b0923df5' 
  AND token = 'uGy7jPA2SI/1+IMhQ0liIkPZPPo9uUn5tVuC41RnUCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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