SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a112905ca8e81e369b374b8f06160710faa9ee27edbaaf5ec2be3cf92ecedd78' 
  AND token = 'Mah+1l0tJ26KtZLTIFQjuPgGq928dQTLEcB4HruX5R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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