SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54062746abdd3d02e0ce7281dca7b51fc57fc2063b042f726453d9a65d1e494a' 
  AND token = 'GSPibN4O/n+0eB70JBFQ9tw6pnyxoo+f6CGcdrW1zr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}