SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61c8e5497bc13c0e57804b331cf4a9c95c2cb96946648e478d6e1b7a3b7e432b' 
  AND token = 'mmX/pJRdjD1GDvPZuwv2iTEoiYmyzwJpHcJVYjJvQSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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