SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ed10be9fd464b0942f7bb38bc0883993e868267d6708986d8c8c55e51cf63ec' 
  AND token = '83WnvTzYy+XQQq4JkgvXwUvm1zDRs+alChGHQNEjlK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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