SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4992e5251c2a8892a1db9642711cb43ee8e8eefb5db7ad1851122a1bf4c0f630' 
  AND token = 'DY1i76Z4n+7N4CIrvmVcyznMN3rrdZk20MLXcKk5fU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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