SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66e02019b0e3c73dd1cc7fb2b82cd29c39782244c0ed75e6007e7ee8ef30d93' 
  AND token = 'BVbVZsPrBNourKzMZdwYv/EQlFFgdzyOmjl0RcjfBx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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