SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94eb611caaba3d0b6ee8853e1f4c6761cf27d1f5ad9e4f4042cf2df7a7e06e83' 
  AND token = '/2VjLQLm6nTImufYP9Dl1YUw7p85+J+SsK/iWzq8opo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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