SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ababd3f13a6cbd9369419b83d532b94925e929cecabc6c9e682b66bf01d3488' 
  AND token = '+E+ZP/MlmS9ogKuQGKmk0Q5GfShz9OzVtyDRBgGqmmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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