SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbb2de7df4ca368f12fb2e919b4def1c469adfd11c503757f7eb34d51b18afee' 
  AND token = 'eIy6WCNPt6zTAYGaJ5ap3ZAyzXPqn6VPOVtr7Kz/+Sc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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