SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4800e408d639b469ed2e033bd7abcb5955adc73562b50510e73be02a5cac605' 
  AND token = 'Dc5oahDGI/dOnhWykYF7xo2OVthakI2b3oEMTPM9uKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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