SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87bb102168907b57c626b8608b520bb4af0ceee88fce7abe0f1b626fd7d4c353' 
  AND token = 'YwzEwuGtDqyvEfR3oDJbzijav9RMRn+3Cy5A7QR0iuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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