SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '079087e02391ba3cfc152fd4326c12472e5be1909ecd222502c32a9676139be6' 
  AND token = 'vRXK1z+qQGcGbFaV9OXxKTSDTDiM0scnenM+ZQf9jE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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