SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4384f98a47e087257329014fd7bacb500ccd674cc3b2d203a76ec95099fed5c' 
  AND token = 'PlICadOEXIRtWeYENNK5LlL69lxxm7mXC1WYCJ95BXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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