SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d9b6872b7b81bbfa3f3108927008df2da1cb5c2eb60882da8f490aa5f94ff55' 
  AND token = 'P5H9Vhnbmkycqk9ryzKaYGqkxoDOsg7jkV+uXFLYlRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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