SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce5bd422c48d10cf1bd3cefb7d3305dc2e6ba60d211577ceb233071c58e18f4' 
  AND token = '3RpMo6PUOxZCeE3Y9ZIawfoPRIcvysIfiXLelIAEakM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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