SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9e4454821cc3875de7c1869546689480b5f5769603710bffecfdcdaa1ce2034' 
  AND token = 'HfBmLz3wLVevh2DRsyvHROXAcgZx6t96K1dABv4BwLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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