SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad74bd56638d1c4d73619d295a0684b672d130af312e8832b3480023c627f9c' 
  AND token = 'GVqtoyMNCRIIKdRl+iRCzdcs22jHTJBKobO8KJ9wUGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}