SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fbd29bdf42f961b28f403fe983d3b0166c39ae18027fed25aecf8d58d4cdd0d' 
  AND token = 'xEPrcj45DJQcYMyotzaBMxKPpq8jiVnMfQeZ/5y2bck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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