SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3763d28215bf3a6561463f617cc78e7d0367f64310c713a7503a19993df23544' 
  AND token = 'wp+AOCPTtZ7spWBhwbxNOP/q/UwWmXKNMRjB9O08OD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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