SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ea4c579e6377b6fdfb8919b616ca48f3034a3ecb798be213f10db88b9bb7a7a' 
  AND token = 'HKEFgLjQZxLBwJs0t7zjgR+tvhxtDXcDs9ymUqGXenA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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