SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4594b9fc3638aef0d0c9846c460f4b38cc8887e8fbb23edfb5f2d197c657867e' 
  AND token = 'ITFL1JEF/b+GBCWfr/5V+EnYRujeKGpaYI/gP9CykKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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