SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e35d6ce36de583e7fe91b1f67fc46114e357821173fb350d5c1b481c36b2ab1' 
  AND token = 'B9viwlP0Svif+iS9spVhJo0NWHTl18fjGJQXuIeB4M4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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