SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6065006fea0b9f14b251a6cdbb290fa6720f2d26bd2f3615ef21bcef7e19ab4' 
  AND token = 'GFgYdzv+pNMom8ZZ2hWSdVpA0Z8K8IjK+LYP1UeiSLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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