SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e77c444b443b32530dbe89db0934c53bcc9a906caa72f1b9dbe9281ea67e8c75' 
  AND token = 'rRU3Z5jo8CxRmUfIpX0dV2dg7+VklF/yRO00fifjszo=' 
  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"
    }
  }
}