SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e66971a95179630d7bbf8f6936802ebc4fccd8f012cb4c5d2f8431de145585' 
  AND token = '+ubjzX3vOKQBAw6ctWyGjX8gK9Dnk1Ja5lOc9ojjm7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}