SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec39bea473ef44ff41f69cf4c01db7cde20a83449a3debaa3cf56a7721fab385' 
  AND token = '4UsxHJMypeEL0GPTrhvSnO2ko874YBAP8OOPAxJWnVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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