SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9ed56c64e39f94465cb27f860152e73b82e38a059657dd14216f79764eb5cc8' 
  AND token = 'jc2z4ChndkYpMROPQagPFEUFsIC1+P6RbfjTWJ5jopg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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