SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae5c7d512caf7513618e8014018dcc41a28e5ef15647e27715cc25a60fc99c7' 
  AND token = 'Gvxseha0AgI5E1A+fg8kDFlsgcYFayAk/JvJKItdZjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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