SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df2e6c65784bcb33e6e28a847ef455a7378188d26badaf8f5b336143a0119d27' 
  AND token = '/rTajqrRMzhbL9sqig+ugrSoe4IMDisNkdQHUcLFZok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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