SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db55727724bc7b364041f01812843bcd9522b631569031e70a0c31b4d7d17f1e' 
  AND token = 'FFV0eNdZ/XWngqwoXAx255yMs8+sdTsPrwIuE7meu50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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