SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0066609d0372213994db8b30b27464196f2b9c2bb32b4860ff22e1c09be2b2c' 
  AND token = 'wRGCz42FPX0bYXz3C65NdIQA+LIeihoiYaSEhrMj5AQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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