SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdad4938b75a18822264128f4fdc6dcb4b43f81aee215dd96b2806820f7f4304' 
  AND token = 'IAXojetIDo/wtgDs6OUG630l68o63SCLW+CapcrWmKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}