SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d1a4d2c0aabfd41cd7277d146f2ef31626509988e9c4d8e5b7b4bcc14c6c840' 
  AND token = 'nWKvw04KdVGgJTyhlqVZfpmOxLNxl7LW53+hTEXPJHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}