SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f22e600134b850d8606c2d8e89e4584af007429a966f3817d5cf7804890ecd6e' 
  AND token = 'zclsH+kfLOg/MZAoLFYdtRSTMyBLqdGFWuPV1Vg+urM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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