SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b45a8af4c3a28c4525b3ef0dd96b65a645b3702998fa8603a45534cad622067' 
  AND token = 'm+rmHX8nFg9zyvGA0b7+2o4UvMuqBUhXPlqMyxK+Dxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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