SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db8b5b4a815d8921cf0328462fb0d9e5f56116154422c01a3fa067fe6ccfb27' 
  AND token = 'YmYCAdyzUFq6n82jSMbfEJWTMGMM0DvlwXb1JjmmUZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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