SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6a6661784755f3a14cb5a1f9cc8eb3bf47e534619a486510846069d7fc94fd6' 
  AND token = 'wUGt84STNECoumhE9mk+peR1u6COkvhzvST0HyNk1dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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