SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb43693014bf4247648775e830350817a7f0f8ff9d6d877ea923112fce2372e0' 
  AND token = '+Gj3aqVmDwDliObxosxEFmrq5yv5647PgvjB5m2LKCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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