SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ac622af94ef92193dca05b7a9a6bbf177378f7855e3338c8129c564c02fa8e7' 
  AND token = 'nNdgsuLvG4y9SEmFi1BMtH3658u+DjoKaRSez+dcUiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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