SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57091514bbf3ae4b5527041fc403c8624a25fb56242153db6169a17b1fee4f32' 
  AND token = 'gUHRJiwYdLLXhMv/Qh05yGLI5YqKpzDaDv2Q63QZ3QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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