SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '652aec9deb182f6768fc5ffd0b42666d243df3687b9604809c9936c5874a1e66' 
  AND token = 'o0p8pt3/+NpNH9Xb5TD44xryuEeTYFc9bP5aqEOSZRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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