SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a91854b22882bbebdb65ab3aff2016760b58bc958bf290fbccd41c004f3252e' 
  AND token = 'WBx164srhMRSE8HrN4IVPvzx/X31Ipd8KdzhwL4a2bE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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