SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '171e8f6ae2f1a30feec428258eaf27425ef8a41be426ca1a07078ef990a9b09c' 
  AND token = 'OlehYYXa9YLfL1sijp8MXylKVrgfMF6MK6wB0ESD5pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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