SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01d762967eceb98d8d3136da564a376ca302a4c472e0620ddd51d41c3dd7f29d' 
  AND token = 'Fa5H17eNMBRdzLgIXcHrCEAO7cOWEF+hMyoooGnTPdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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