SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c1c415d75fce8947f7274a3b7a5347f1e29141b0923b72e60a4248aa2a76d61' 
  AND token = 'HHjGLutVuo4Dmh2hIExvsBLxrIPYRzRhxC3pwUca2bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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