SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '896f00dc03377602025624ba7f7fc2608db5bfa00a33ab2c2f11b7d199efb706' 
  AND token = 'g4iUBVs+QH+TlmhFP2BClPZyY5qELrQh7a/1QsWwN4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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