SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5ed096e665d52ddcb6e5d3458a8d69aa7780710484fecd919eed9ec0661a0e0' 
  AND token = 'rXU1xTfBD/Dgznw2oW6eX6OIxiRj7Mbdd5Hym5BKhfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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