SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4724fc296f478f06e01662862ac2e3454f640069246eeb5b720370d5b91a7708' 
  AND token = 'EcgEkZBqENXEQPe4t1NYYdaBvJRO5SVHcTRkPrix3FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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