SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '191749eb613ccd3c025fa299287ccdfd4a179b71155f4147f1a05c40cbcd25c3' 
  AND token = 'pUzSHW0PSAhqhPTh2Ghklnvmup+BDr3jooki4J+mOw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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