SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a52ba95d60a1c47c9c1828e2e7603f8d83c4f42130fa5a84cede30237e26101' 
  AND token = 'LOiVVpW+JVKQhAry3sXKMX52KGTn68xKDxqbInzojRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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