SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '92f112e99e89a88cdef41402079e39cd0d451bc5f6f6120dbdde7cfd0d584e78' 
  AND token = 'qhMLduHcxmLUU1cUdIMZAhSLQR9IF/xQBFyPUBveelo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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